Image sensors and displays are generally formed from crystalline silicon substrates, thin films deposited on glass, or other somewhat rigid and brittle materials. These materials result in displays such as liquid crystal displays (LCD), and imaging arrays, such as charge-coupled devices (CCD), that are generally flat. Flat image sensors have limitations as to the field of view, and rely upon complex and expensive optical systems to widen the field of view, while a spherically curved sensor gives a wide field of view with simple optics. Curved displays may be required in certain applications depending on the positions from which it is intended to be viewed and the form of the structure that supports the display.
The ability to curve these arrays would allow for wide angle imaging systems, whether for sensing or viewing. Forming a curved array of pixels for either sensing or display gives rise to a number of issues. The advent of flexible electronics has made possible conical or cylindrical array surfaces, mostly based upon bending rectangular arrays. Formation of a spherical array is much more complex in several aspects, including manufacture, addressing, and image processing.
Some approaches of manufacturing conformal electronics manufacture the electronics on a flat, flexibly substrate and then make cuts to allow the substrate to bend to the desired shape. The process of bending the substrate may result in stress concentrations at points with very small curvatures that may cause cracking in the overlying films.